Hewlett-Packard sued Oracle on Wednesday over Oracle's decision to stop developing software for Intel's Itanium processor, the chip used by HP in its high-end servers.

HP said it believes Oracle's March 22 decision to discontinue all future software development for Itanium violates "legally binding commitments" that Oracle made to HP and the companies' 140,000 joint customers, HP said in a statement.

"Further, we believe that this is an unlawful attempt to force customers from HP Itanium platforms to Oracle's own platforms," HP said.

HP filed its lawsuit Wednesday in the Superior Court in Santa Clara, California, in a bid to force Oracle to reverse its decision. HP believes Oracle is "legally obligated" to keep developing its software for Itanium, HP said.

Oracle shot back that HP's claims are untrue and accused HP of tricking it into signing an agreement last September to continue its support for Itanium, even though HP knew of an Intel plan to discontinue Itanium.

"We believe that HP specifically asked Oracle to guarantee long-term support for Itanium in the September of 2010 agreement because HP already knew all about Intel's plans to discontinue Itanium, and HP was concerned about what would happen when Oracle found out about that plan," Oracle said in a statement.

Intel has not publicly announced any plans to stop developing Itanium. "HP remains committed to a long-term mission-critical server roadmap, including Intel's Itanium processor. Similarly, Intel has repeatedly reinforced its ongoing commitment to the Itanium roadmap," HP said in its statement.

But Oracle insisted that HP is misleading its customers. "Intel's plans to end-of-life Itanium will be revealed in court now that HP has filed this utterly malicious and meritless lawsuit against Oracle," the company said.